Switch-indicating means



b11824; 1930- c. w. PRESCOTT swn'cn INDIGATING MEANS Original Filed April 16 1925 INVENTOR. Ev -WW %@TORNEY Patented June 24, 1930 UNl'lED STATES PATENT QFFICE CHARLES W. PRESCOTT, OF MILL HILL, ENGLAND, ASSIGNOR TO GENERAL RAILWAY SIGNAL COMPANY, OF ROCHESTER, NEW YORK SWITCH-INDICATIN G MEANS Original application filed April 16, 1925, Serial No. 23,543. Divided and this application. filed June 2, 1927'. Serial No. 196,156.

This invention relates to indicating apparatus and has more particularly reference to such apparatus used in connection with a railway switch.

The present application is a division of applicants co-pending application Ser. No. 23,5l3 filed April 16, 1925, fortrafiic controlling system.

In operating a railway switch, more particularly when the operation is effected from a point distant from the switch, it is desirable to know, at all times, the existing position of such switch and whether or not a section of track adjacent the switch be occupied.

With the above and other considerations in mind, it is proposed in accordance with this invention, to provide indicating apparatus satisfying the above conditions.

Further objects, purposes, and characteristic features of the invention will appear as the description progresses, reference being had to the accompanyin drawings, showing solely by way of example, two forms of the invention, and wherein Fig. 1 is a diagrammatic showing, exemplifying the invention, of a system for indicating the position of the switch points of a railway switch, and the occupancy of an adjacent detector track section.

Fig. 2 is a diagrammatic showing of a second form of indicating apparatus in accordance with this invention.

Referring to the apparatus shown in Fig. 1, a track battery 190 is provided at the exit end of a detector track circuit, normally energizing a track relay TR connected across the entrance end of this track circuit. An insulated movable contact block 191 carrying a U-shaped metallic contact finger 192 has been represented as being connected to the throw bar 46, of the track switch, this representation being merely diagrammatic and it being assumed that the contact block '191'is operated in practice by a suitable cam are energized in series through the following circuit :-from the battery terminal B, wire 193, stationary contact 194 movable contact 192 and stationary contact 195, wires 196 and 197, winding of the relay HR, wire 198 and Winding of the relay LR to the battery terminal C. With the relays LR and HR energized, a circuit for energizing the normal indicating light N is completed, which circuit may be traced as follows from the positive terminal of the battery 199, wires 200 and 201, contact finger 202 and front contact of the relay LR, wire 203, contact finger 20a and front contact of the relay HR, wire 205, indicating lamp N, and wires 206, 207 and 208 to the negative terminal of the battery 199. When the switch points 17 are thrown to their reverse position, a second circuit through the windings of the relays LR and HR is completed, which circuit may be traced as follows from the battery terminal B, wire 210, stationary contact 211 movable contact 192 and stationary contact 212, wire 213, resistance unit 21%, wires 215 and 197, winding of the relay HR, wire 198 and winding of the relay LE to the battery terminal C. The relays LR and HR are so constructed and arranged that the current flowing through their windings in the circuit just traced through the resistance unit 21 is sufficient to maintain the contact finger 202 of the relay LR in its attracted position, but is insufficient to maintain the contact finger 20 attracted, so that the contact finger 202 will engage its front contact while the contact finger 20 1 will engage its back contact. The relays HR and LR may be constructed to attract their con tact fingers at different values of current by properly proportioning the resistance of their respective windings, the relay HR having a high resistance and the relay LR having a low resistance, or any other suitable expedient may be resorted to, to accomplish this feature. Under these conditions, an energizing circuit may be traced as follows: from the negative terminal of the battery 199, wires 200 and 201, contact finger 202 and front contact of the relay LR, wire 203, contact finger 204 and back cont-act of 241 to the secondary winding of the transformer 222.

hen the switch points are thrown, the track indication light X will remain illuminated as the contacts for closing the circuits through the condenser 235, the resistance 248 and the reactance 255 are arranged to close each successive circuit before the previous circuit is opened. It will be observed that when a train enters the detector track circuit, the current from the transformer will be shunted through the wheels and axles of such train, cutting oil the current flowing through the phase winding 223 and the track circuit indicating light X. With the phase winding 223 tie-energized, the track relay 1 swings its contact 242 to the control or t le-energized position, thus de-energizing the indication light It or N and indicating that the track circuit is occupied by the tact that all of the indication lights, X, R and N are extinguished.

The above specific description of apparatus embodying this invention is given solely by way of illustration, and is not intended, in any manner whatsoever, in a limiting sense. Obviously this invention can assume many dii'erent physical forms, and is susceptible of various modifications, and all such. forms and modificationsare desired to be included by this invention, as come within the scope of the appended claims.

Having described the invention I now claim:

1. In an indicating system for track switches, section of trackway provided with a track circuit and a track switch, a polyphase track relay having one of its windings connected in said track circuit, an indicating device connected in said track circuit, means for changing the phase relation of the current to the voltage in said track circuit in accordance with the position of said track switch, and indicating devices controlled by the position of said polyphase track relay.

In an indication system for track switches, a section of trackway provided with an alternating current track circuit and a track switch, a polyphase track relay having one of its windings connected in series with said track circuit, means for \cirying the electrical constants of said track circuit in accordance with the position of said track switch for operating said track .v, track indicating device connected in es with said track circuit, and switch icating devices controlled by the position of said track relay whereby said track indica. g device may be maintained energized while said track switch is being operated.

3. in an indicating system for track switches, section of track, a track switch in the section of track, distinctive indicating means for indicating the position of the track switch, relay means controlling the indicating means, track switch controlled means for controlling the relay means by causing distinctive current flows through the relay means, and a track occupancy indicator connected in circuit with the relay means and unatl'ected by said distinctive current flows as such.

4. In an indicating system for track switches, a section of trackway provided with a track circuit and a track switch, a polyphase track relay having one of its windings connected in said track circuit, means for changing the phase relation of the current to the voltage in said track circuit in accordance with the position of said track switch, and indicating devices con trolled by the position of said polyphase track relay.

5. In an indication system for track switches, a section of trackway provided with an alternating current track circuit and a track switch, a polyphase track relay having one of its windings connected in series with said track circuit, means for varying the electrical constants of said track circuit in accordance with the position of said track switch for operating said tracl relay, and switch indicating devices controlled by the position of said track relay.

6. In an indicating system, a polyphase relay, distinctive indicators, governed by the relay, a track switch, and means controlled by the position of the track switch to vary the phase of the current to its voltage in one phase of the relay.

7. In an indicating system, a polyphase relay, distinctive indicators governed by the relay, a track switch and means to cause the current in one phase winding of the relay to lag, to be in phase with and to lead, its voltage, as the track switch is moved from one extreme position to the other.

In testimony whereof I a-ffix my signature.

CHARLES W. PRESCOTT. 

